The Efficacy and Safety Study of High Dose Donepezil in Parkinson's Disease With Dementia

The Efficacy of 23mg Versus 10mg of Donepezil in ParkInson's Disease With Dementia

The purpose of this study to evaluate the safety and efficacy of high-dose donepezil (23mg) in Parkinson's disease with dementia compared to standard dose donepezil.

This study is open-label, prospective, randomized paralleled study. The investigators evaluate the efficacy of high-dose donepezil in patients with Parkinson's disease with dementia (PDD) who have taken standard donepezil (10mg) for 12 weeks. The participants, who sign the informed consent, are assigned into two groups randomly (high-dose donepezil group and standard donepezil group). All participants will be maintained the medication for 24 weeks and assessed cognitive function at 24 weeks. They will visit to clinic for 3 times (4, 12, 24 weeks) to assess cognitive function and adverse event. After the end of study, all participants were administrated by standard dose donepezil again.

Inclusion criteria :

• Patients diagnosed as Parkinson's disease according to Queen Brain Bank criteria
• Patients who have been diagnosed as dementia after diagnosing Parkinson's disease at least 1 year.
• Patients with Hoehn and Yahr staging from 2 to 4
• Patients with MMSE score from 10 to 24
• Patients who have taken donepezil for at least 12 weeks before screening period
• Patients whose medications for Parkinson's disease have not change for 1 month
• Patients who give informed consent

Exclusion criteria :

• Patients who cannot be performed neuropsychiatric test because of hearing and visual difficulty
• Patients who have taken medicine affecting cognitive function such as anticholinergic drug and memantine -Patients diagnosed as dementia with Lewy body and vascular dementia-
• Patients who have history of neurosyphilis, head trauma, encephalitis or other movement disorders
• Patients who have psychiatric disease
• Except patients who are stable state under antidepressant or atypical neuroleptics
• Patients with child-bearing periods
• Patients who have severe liver or kidney disease necessary for aggressive treatment
• Patients who have gastrointestinal disease needed for treatment
• Patients who cannot taken tablet per oral
• Patients who are participated in other clinical trial except observational study